..
While computers are not yet so superb at all aspects of the game as to be
sufficient to accurately judge positional play/longrange strategy, they are
sufficiently good to passably rate the play of patzers, which constitute the
vast majority of chessplayers.
As one famous player put it: chess is 99% tactics.



As for the attempt to compare ratings of players from different pools, the
whole point would be to eliminate such isolated pools, by effectively tossing
everyone into the same pool: the pool of all chessgames ever played.
All such games would be evaluated by a chess program (or programs) objectively.
The computer would not know or care who played the White pieces, or the Black.
Its evaluation would come out precisely the same for a game between you and I,
as for a game between Lasker and Capablanca, provided we followed the same
moves:


/* 1.e4 e5 2.Nf3 Nf6 (draw agreed)//


*zero significant errors detected*
*premature draw penalty applied*

ratings dump:

1.Terrybean = 2600
2.Nomorechess = 2625
3.Lasker = 2600
4.Capablanca = 2625